Design And Test Of Server Application Software In AMR Using DLMS/COSEM

With the rapid development of social economy and communication technology,a variety of smart meters come into being,but have not been able to form a unified and open automatic meter reading(AMR)system.To improve this situation,the International Electrotechnical Commission(IEC)proposed the Distribution Line Message Specification and Companion Specification for Energy Metering(DLMS/COSEM)communication protocol.Because of using the object-oriented method to realize the data acquisition in the AMR system and the metering system,the DLMS/COSEM communication protocol has excellent system interconnection and interoperability.Widely used in Europe and the United States,the DLMS/COSEM protocol standard has become a comparatively perfect meter communication protocol standard so far.Therefore,developing and designing the AMR systems which support the DLMS/COSEM communication protocol will not only improve the efficiency of data collection but also promote the technical level of China on AMR system.Moreover it will also bring significant social and economic benefits.In this thesis,we design and develop a server application software and a testing software of AMR system based on the application layer protocol specification of the DLMS/COSEM.Then the testing software conducts a function testing on the server application software by simulating the information exchange between the client application layer and the server application software.The main contents and results are as follows:First,the application layer protocol specification of DLMS / COSEM protocol is introduced.Then,an in-depth study of the ASN.1(Syntax Notation One)syntax is made including its BER coding and A-XDR coding rules.Second,we design an AMR system server application software which support DLMS / COSEM communication protocol based on the Winpcap(Windows packet capture)development interface.Also,we develop this application software on the Visual Studio platform using the hierarchical modular scheme.The application layer is in charge of providing the framework for transmitting information.And the application layer can achieve the APDU(Application Protocol Data Unit)reception and response with the client by capturing and sending Ethernet frames.Moreover,the application layer can realize the analysis and encapsulation of APDU based on ASN.1 syntax.The application process can check and respond to the connection establishment request,GET request and SET request from the client and provide the interfaces for the application software to access the interface class object libraries of the meter instruments.Furthermore,in order to verify the function of the server application,we develop a testing software with visual interface based on WPF(Windows Presentation Foundation)framework and modular design.The testing software consists of the front-end application and the back-end system.The front-end application realizes the function of providing the testers with visual choice of test cases and display of test results.And the back-end system is in charge of executing the test cases and checking the response of the server application software.Finally,we test the function of the server application software in terms of the connection establishment,GET service and SET service.In the test of each service,we first analyze part of the test cases and then implement all the test cases of this service.The results show that we have completed the application software design of the automatic meter reading system supporting DLMS/COSEM which was based on the application layer protocol specification for DLMS/COSEM series protocol and realized the function of connection establishment,GET service and SET service.The research content of this paper not only verify the feasibility of DLMS/COSEM application layer communication protocol,but also lays a good technical foundation for the development of smart meters and AMR systems using DLMS/COSEM protocol communication.